ABSTRACT
Background: Long-term complications of COVID-19 in hematopoietic stem cell transplant (HCT) recipients are unknown. Recent studies have described short term outcomes of COVID19 infection post allogeneic (allo) and autologous (auto) HCT. In this study we provide long term follow-up of the outcomes of COVID19 infection in allo and auto HCT recipients. Methods: We performed a retrospective study of adult patients who have received allo or auto HCT and were subsequently diagnosed with COVID-19 infection between March-December 2020. We summarized patient characteristics, laboratory and treatment data related to COVID-19 infection in these patients. Results: In this study, we provide long-term follow-up of over 7 months. Fifteen patients were identified for inclusion (allo n = 12, auto n = 3). Median follow-up was 7.8 months (range 1.9-10.7) for surviving patients. Median age at COVID-19 diagnosis was 55 years (range 24-77). Most patients were > 1 year out from transplant (allo n = 10, auto n = 1, 73%). Two patients (allo n = 1, auto n = 1, 13%) had undergone transplant within the preceding month. Most allo patients (n = 11, 73%) had received myeloablative conditioning. At the time of COVID-19 diagnosis, 9 allo patients (75%) were on immunosuppression (IS) (n = 7 for chronic graftversus-host-disease (GVHD);n = 2 for GVHD prophylaxis). Eleven patients (73%) required hospitalization (allo n = 9, auto n = 2). Per the National Institutes of Health definitions of COVID-19 illness severity, 3 patients had critical disease (allo n = 2, auto n = 1, 20%), 5 severe (allo n = 5, 33%), 3 moderate (allo n = 2, auto n = 1, 20%), and 4 mild (allo n = 3, auto n = 1, 27%). All patients with chronic GVHD required hospitalization. Two patients died (allo n = 1, auto n = 1, 13%)-both had critical COVID-19 infections, were > 65 years old, > 3 years out from transplant, and had significant comorbidities. The allo patient was receiving prednisone < 1 mg/kg for chronic lung GVHD at COVID-19 diagnosis. Two allo patients developed either acute GVHD or chronic GVHD exacerbation within 3 months of their infection. One patient developed biopsy-proven acute GVHD (max grade III) 3 weeks after her infection and another patient developed a severe exacerbation of chronic GVHD within 3 months-both continue to require multi-modal IS. The remaining 7 patients with chronic GVHD have been maintained on either stable or tapered IS. Conclusions: Given the effect of COVID-19 infection, its impact on HCT recipients is important to define. The majority of HCT patients who contracted moderate-critical COVID-19 infections in our study were either on IS or had significant comorbidities. Our observational data points to the importance of long-term follow-up in HCT patients. Future studies are needed to delineate whether there is a relationship between COVID-19 infection and GVHD development or exacerbation. The role of vaccination in HCT recipients remains to be explored.